Dental chair



DENTAL CHAIR 5 Sheets-Sheet 1 Filed on. 24, 1965 N mfi .l s m C N N 4 Fm NNW. T G A F &m RH Am P VA 3 4 m o- 4. 2 4/ 3 4 f r w P v 7 4 6 x 4 4My 2 4 3 mm F 12, 1967 c. E. VA-UGHN ETAL 3,357,740

DENTAL CHA IR 5 Sheets-Sheet 2 Filed Oct. 24, 1965 INVENTORS CHARLES E.VAUGHN AND BY ARTHUR GILBERT BILLIN ATTORNEYS 1967 c. E. VAUGHN ETAL3,357,740

DENTAL CHAIR Filed Oct. 24, 1965 5 Sheets-Sheet Z FIG. IO

INVENTORS CHARLES E. VAUGHN AND BY ARTHUR GILBERT BILLIN JAM J2EE,

ATTORNEYS United States Patent ()fiice 3,357,740 Patented Dec. 12, 1967a corporation of Delaware Filed Get. 24, 1965, Ser. No. 504,664 1 Claim.(Cl. 297-416) This invention relates to dental equipment and, moreparticularly, to the construction and arrangement of the two majorelements of dental equipment for the convenience of the dentist and topromote his efliciency.

In recent years, much attention has been given to studying the motionsof a dentist. Dentists have been subjected to time and motion studies inan effort to improve their efi'iciency and reduce fatigue. The problemdoes not present an easy solution since the equipment must beconstructed and arranged to accommodate the short dentist, the talldentist, a dentist who desires to stand up during a major part of hiswork, and a dentist who likes to sit down while performing most of hisoperations. The problem is still further complicated by the fact thatthe same fundamental equipment must be used, unless the dentist has aseparate operating room, for operating on tall patients, short patientsand children.

An object of our invention is to provide a dental chair in which theelements thereof are more maneouverable than those employed in the pastwhereby the relationship between the dental instruments carried by adental stand,

the patient and the dentist are improved and more flexible.

Another object of our invention is to provide a dental chair in whichthe elements thereof are readily adjustable so that the dentist isalways able to get the patients mouth into a relationship with thedental instruments such that it meets his convenience regardless ofWhether he is tall, short, desires to stand or sit down during hispractice, or whether the patient is tall or short.

More specifically, our invention contemplates a dental chair, the backand combined seat and footrest of which may be placed in an infinitenumber of relationships to meet the convenience of the dentist; combinedwith mechanism for raising and lowering the chair; and combined with amobile base for the chair on which the chair may slide with relation tothe usual associated dental unit whereby once the dentist has selectedthe patients head to dental instruments distance or relationship hedesires to use, he may maintain this same distance regardless of whetherhe wishes to operate on the patient in substantially an uprightposition, in a substantially fully reclining position, or in anyintermediate position.

My invention further contemplates an improved structure or enablingconvenient ingress and egress of the patient to and from the chaircombined with mechanism for causing the dental chair arms always tofollow the position of the patient seated or reclining in the chair.

Other objects and advantages of this invention will be particularly setforth in the claim and will be apparent from the following description,when taken in connection with the accompanying drawings in which:

FIG. 1 is a side elevation of the chair of our invention with partsbroken away better to illustrate its construction, the chair beingarranged with the back in an upright position with respect to thecombined seat and footrest;

FIG. 2 is a bottom plan view of the chair base and taken substantiallyon the line 2-2 of FIG. 1 in the direction indicated by the arrows;

FIG. 3 is a top plan view of the chair base track taken substantially onthe line 33 of FIG. 1 in the direction indicated by the arrows;

FIG. 4 is a sectional view taken substantially on the line 4-4 of FIG. 3in the direction indicated by the arrows;

FIG. 5 is a perspective view of a part of the chair arm operatingmechanism;

FIG. 6 is a perspective view of the removable chair arm;

FIG. 7 is a view showing the plate carried by the chair in which theremovable chair arm of FIG. 6 may be lodged, locked and connected withthe arm operating shaft;

FIG. 8 is a face view of FIG. 7;

FIG. 9 is a fragmentary view in side elevation of the top of the dentalunit and illustrating how the dental instruments may be extended;

FIG. 10 is a view showing the chair in an upright position with apatient supported therein;

FIG. 11 is a view similar to FIG. 10 in that it illustrates the samepatient mouth to dental instruments relationship with the patient in asemi-reclining position in the chair; and

FIG. 12 is a view similar to FIGS. 10 and 11 showing the same mouth toinstruments relationship but with the patient in an almost fullyreclining position.

One important aspect of our invention (FIGS. 10 to 12) concerns therelationship of the dental chair, generally indicated by the numeral 14,and a dental unit, generally indicated by the numeral 16, and theirrelationship with the mouth of a patient seated in the dental chair. Therelationship of these three factors together with the physicalproportions of the dentist, and whether the dentist prefers to sit downor stand up for performing his work, are extremely important in cuttingdown the number and amplitude of the movements of the dentist innormally carrying out his practice and his fatigue at the end of a day.

The dental unit (FIGS. 10 and 11) comprises a stand 17, a panelgenerally indicated by the numeral 18, and an automatic drinking cupfiller (FIG. 10) generally indicated by the numeral 19. The instrumentpanel 18 comprises an instrument holder 21 adapted to be housed withinthe dental unit 16 when not in use and adapted, when in use, to pivot tothe position shown (FIG. 9) or any intermediate position as indicated bythe dotted lines. The instrument panel may be similar to that shown inBronk Reissue Patent 24,08-7 issued Nov. 15, 1955.

The instrument holder 21 has a plurality of sockets for the reception ofretractable instruments 22. In the instant case we have shown fiveretractable instruments which may be one or more highspeed handpieces, alow speed handpiece which may be similar to that shown in applicationSer. No. 347,813 filed Feb. 27, 1964; a cantery; and a syringe which maybe similar to that shown in application Ser. No. 399,482 filed Sept. 28,1964. All of the instruments are retractable to the positions shown inFIG. 9 by a mechanism which may be similar to that shown in the lastmentioned application.

All of the above instruments are subject to constant, repetitive andsuccessive use by the dentist during the normal course of a day. Perhapsthe dentist will have to reach for one of the instruments and apply itto the mouth of a patient several hundred times during the course of aday. Moreover, usually the dentist has his eyes fixed on the mouth ofthe patient and it is therefore desirable that he be able to reach andextend the instrument for use without looking at the instrument andsolely by feel. Some dentists, possibly a majority of them, prefer towork, regardless of the position of the dentist, with the instruments aconstant distance away from the patients mouth.

The relationship of the parts shown in FIGS. 10-12 inclusive is such asmight be desired by a relatively short dentist operating in. a stand-upposition, or a relatively tall dentist operating from a seated positionon a stool adjacent the dental chair. While we have shown one specificarrangement of the patients mouth with relation to the dentalinstruments, it will be obvious from the description that follows, thatany desired relationship of the elements may be obtained to suit thepreference of any particular dentist because of the versatility ofpositioning the patient in relationship to the dental instruments.

The dental chair shown is in general of the lounge type and includes aseat 26 which may be contoured to comfortably receive the patients seatand upper and lower legs. Attached to the seat 26 is a foot rest 27, theseat rest and footrest being movable as a unit. Pivoted at the rear endof the seat rest 26 is a backrest 28. In the particular form of thisinvention, the backrest may be manually pivoted with respect to the seatrest as it has been found that this operation of the chair does notnecessarily have to be power operated.

Carried by the backrest, preferably at the sides of the chair or anyother convenient location, are a plurality of push-buttons 29. In thiscase, four push buttons have been shown, two are provided to energizemotors or a hydraulic mechanism for tilting the backrest about ahorizontal axis 35. The two other push buttons are for the purpose ofraising and lowering the entire chair by applied power such as electricmotor, but more usually, by a hydraulic system. The chair includes ahousing 31 which has a pair of telescoping hydraulic cylinders 32 forthe supporting and raising and lowering of the chair. These parts haveonly been diagrammatically illustrated since their function andoperation are well-known in the art to which this invention applies.

Mounted adjacent the side of the chair is a lever 36. As previouslymentioned, the backrest 28 is pivoted with respect to the combined seatand footrest 26-27 so that the backrest 28 may be positioned by rotationon a pivot (not shown) in any desired angular relatiorship to the seatrest 26. When released, the hand lever 36 automatically locks thecombined seat and backrest in any desired position. Preferably, thelever 36 is hand operated and depressed to release the lock; thebackrest and seat rest may then be shifted as a unit about a horizontalpivot to the various positions shown in FIGS. to 12. The seat unit isrelocked again with respect to the base automatically upon release ofthe lever 36.

The housing 31 is mounted on a base 38 which is essentially rectangularin shape. The underside of the base is shown in FIG. 2. The base hasdepending side edges or a rim 39 and the forward and rearward ends carrylegs or bosses 41 integral with the base casting. Legs 41 and the rim 39carry rollers 42 mounted in the corners of the bottom plate. The rollersride on V-shaped tracks, generally indicated by the numeral 42-, asectional view of one of which is shown in FIG. 4. The track is made oftwo U-shaped sections 43 and 44 which are identical and oppositelydirected. The tracks 43 and 44 are provided with interfitting parts 46whereby the track section may be separated for shipment and be readilyerected. The track sections may be bolted to the floor. However, theweight of the chair is sufiicient to hold the tracks in position andbolting to the floor is unnecessary so that if desired, the chair may blifted off the tracks to adjust the position of the tracks in relationto the dental unit. Carried by each of the tracks are stops 47 which arelocated adjacent the center of the track so that in any position of thebase on the track, the stops 47 are hidden from view. More important,the location of the stops is such that the dentist cannot stumble overthem in moving about the chair. The stops will always lie beneath thebase and do not consti-. tute a hazard to the dentist.

Mechanism is provided to lock the base with respect to the floor andtrack which comprises a foot pedal 51 which is located centrally of thebase so that it may be foot operated conveniently by a righthandeddentist standing in the foreground of FIG. 1 or a left-handed dentiststanding in the background of FIG. 1. It will readily be apparent thatother adaptations may be made in the chair to set the chair up for aright-handed or left-handed dentist, as for example, the location of thepush buttons 29.

The foot pedal is mounted on a post 52 (see FIG. 2) connected to a lever53 by a pin. The lever 53 is pivoted at 54 on a bracket carried on theunderside of the base. The upper end of lever 53 is pivoted or biaseddownwardly, as viewed in FIG. 2, by a spring 57 fixed as shown at 58 toa plate 59 carried on the underside of the base plate. This raises thefoot pedal 51 as shown in FIG. 1. A brake-pad 61 is provided at the endof the lever so that when the dentist releases foot pedal 51, the spring57 automatically rotates the lever 53 about the pivot 54 to apply thebrake-pad 61 to the floor. The brake is released by pressing downwardlyon the foot pedal 51. When the brake-pad is in contact with the floor,the chair may be pushed along the track only with great diificulty andthe chair is, for practical purposes, locked in position.

Referring now to FIGS. 1 and 5-8 inclusive, the arms 66 and 67 arearranged so that one of the arms, in the case of a right-handed dentistthe forward arm 66 as viewed in FIG. 1, is removable as will presentlyappear. The rearward arm 67 is pivoted by means of a link on a pivot 68to a rod 69 pivoted to a link 71 pivoted on the bottom of the arm 67.Mounted in the back of the chair is a cross assembly, generallyindicated by the numeral 72 which carries a shaft 73 which extendscompletely across the back of the chair. The shaft 73 rotates or moreaccurately, oscillates between a position in which the arm 67 is in itslowermost position as shown in FIG. 1 in which position the arm 67 issubstantially horizontal, to the uppermost position which occurs whenthe backrest 28 is in the lowermost position as shown in FIG. 2.

The arm 67 has a sleeve section 96 which has clutch faces 97 whichengage clutch faces 75 formed on the sleeve 117 and pinned as shown at118 to the shaft 73. The sleeve 117 is free with respect to the bracket76 which is fixed to the back of the chair by means such as slots andscrews. The bracket 76 includes a pair of integral bracket arms 77-78.

Mounted on the shaft 73 is a brake assembly generally indicated by thenumeral 81. The brake assembly comprises a brake disc 82 secured to theshaft and a pair of brake shoes 83 mounted on opposite sides of brakedisc 82. The brake shoes 83 may be made of nylon or any suitablematerial. The nylon brake shoes 83 are pressed into engagement in thebrake disc 82 by a pressure plate 86 and a plate 87 fixed by means oftie rods 88 to the bracket arm 78.

Rods 91 extend from the backing plate 87 through openings in thepressure plate 86 and the pressure plate is urged to the right, asviewed in FIG. 5, by means of springs 92 which seat against nuts 93threaded on the ends of the rods 91.

The arm 66 has a sleeve section 96 (FIG. 6) which has clutch elements 97integral therewith. Carried by the side of the chair are fittings 99.The fittings are identical on each side of the chair and are fixed tothe chair. The sleeve 96 at the right (FIG. 5) rotates in an opening 101(FIG. 7) formed in the fitting 99. A pin 98 extends from the arm sleeve96. The fittings 99, for convenience of the manufacturer, are made up ofstacked plates so that the opening 101 may be provided with anirregularly shaped groove.

The arm 66 is removable from the chair and is also freely rotatable froma substantially horizontal position to any one of the positions shown inFIGS. l0, l1 and 12 and to a vertical position. In a vertical positionthe pin 98 is in registry with a horizontally extending slot 103 makingit possible for the dentist to remove the arm 66 when desired.

FIG. 7 is a perspective view looking in general from the left of FIG. 5.The groove from the horizontal slot 103 has a wall 104 and the pin 98rides on this wall through approximately This allows the arm 66 to movethrough approximately 90 and also allows the arm to be moved to asubstantially vertical position at which time the pin 98 is in registrywith the horizontally extending slot 103 and the arm may be removed.

The clutch faces of the clutch element 97 (FIG. 6) butt against and aredriven by clutch elements 106 formed on a clamp 107. The clamp is madeup of a block of metal slotted and clamped together by screws 108. Theclamp member 107 has a bore so that upon tightening the screws 108 theclamp may be rigidly connected to the shaft 73.

From what has been described it will be clear that movement of the arm67, at the left of FIG. 5, rotates the shaft 73 and through the clutchelements previously described, the arm 66. The fixture 99 at the left ofFIG. 5 has an eifective circular opening to accommodate a sleeve 96 andcannot be removed from the chair. By turning the assembly 72 end for endand changing the location of the rod 69, the arrangement of chair armsmay be transposed so as to convert the chair from right-handed toleft-handed for the convenience of left-handed dentists. The purpose ofthe clutch assembly 81 is to cushion the fall of the arm 66 and preventit from dropping heavily on the arm of a patient and minimize noise.

While we have shown and described the preferred form of mechanism of ourinvention, it will be apparent that various modifications and changesmay be made therein,

particularly in the form and relation of parts, without departing fromthe spirit of our invention as set forth in the appended claim.

We claim:

A dental chair comprising the combination of a seat and a back pivotedthereto:

(a) a pair of chair arms;

(b) a link pivoted to the seat and one of said arms;

(0) an oscillatable shaft extending across the back and connected to theother arm so that when the back is pivoted with respect to the seat botharms move together as a unit;

(d) a disconnectable clutch between said other arm and said chair;

(e) means for removing said other arm from said shaft when said otherarm is in a substantially vertical position; and

(f) means in connection with said shaft for braking the fall of saidother arm from a position above the horizontal toward a horizontalposition.

References Cited UNITED STATES PATENTS 2,271,007 1/1942 Hanna 18852,286,372 6/1942 Page 297-217 2,661,227 12/1953 Murphy 297-417 2,713,8917/ 1955 Linquist 297416 3,172,699 3/1965 Naughton 297417 3,259,3557/1966 Slouka 297-344 FOREIGN PATENTS 590,836 7/1947 Great Britain.

FRANCIS K. ZUGEL, Primary Examiner.

